If you can get the band on-board, any number of sea chanteys are contra-tune-able--for instance, Drunken Sailor and South Australia, in addition to the sea songs already in the repertoire like Sailor's Hornpipe (which turns up in the Popeye theme!). Also, He's a Pirate from Pirates of the Caribbean is loads of fun to dance to (I've got a version that I engraved if you/the band wants).
As far as dances in the theme, A Pirate's Life for Me by Nathaniel Jack, High Seas by Diane Silver, and Captain Shank's Revenge by Maggie Jo Saylor all come to mind, and I'm sure there are loads more! (Though my favorite part about Captain Shank can be applied to pretty much any dance: in a Petronella, instead of clapping, shout "yo ho!")
If it's a gender-neutral dance, call with Ports and Starboards?
And my current favorite joke:
"What do octogenarian pirates say?"
"Aye, matey!"
Best of luck--sounds like fun!